Hambro Composite Floor System

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With its Hambro composite floor system, Canam meets the needs of the multi-residential, mixed-use, singe-family home and commercial markets by offering optimized construction solutions.

Canam offers to owners, real estate developers and general contractors an array of structural components, including the Hambro D500 and MD2000 composite floor systems, a composite girder and a transfer slab system which can be combined in order to design better adapted and more functional buildings.

Favored on load-bearing walls

The Hambro D500 composite floor system is the economical solution to meet the challenges associated with floor construction. This system is ideal on load-bearing walls made of light gauge steel, wood, concrete block, masonry and structural steel. It combines the flexibility of the D500 steel joists with a transversely reinforced concrete compression slab.

Composed of reusable plywood, from story to story, this system requires stripping. The speed of installation allows an earlier availability to other trades.

Benefits

Fire resistance: The Hambro system complies with UL/ULC/cUL standards.

Long spans: Hambro joists can span up to 43 ft. (13.1 m) without shoring.

Rigidity and strength: Enhanced strength due to composite action between the steel and concrete.

Versatility: Applicable to all types of framing.

Service: Design assistance, value engineering and fast delivery.

Simplicity: Fast and simple to install.

By combining Hambro steel joists with the poured concrete, the system forms composite T-beams that are integrated in the transversally reinforced continuous slab. The bottom chord acts as a tension member during the concreting process while the web systems, which are made from bent rods, serve to resist vertical shear.

The top chord withstands compressive action during the non-composite stage and subsequently functions as a continuous shear connector between the steel and concrete through adhesion and friction. The slab is reinforced with welded wire mesh.

The reinforced concrete slab also contributes to the transfer of horizontal loads (wind, seismic activity) and acts
to stiffen multistory buildings.

Installation

This system is strongly recommended by builders.

1. POSITIONING OF JOISTS
The joists are placed on the walls or beams and positioned in compliance with the shop drawings issued for construction by Canam. The joist connection methods are also shown on the Canam drawings.

2. ROLLBARS
The rollbars are designed to support the plywood forms, concrete construction load. When rotated and locked into the notches in the top chord, the rollbars lock the joists in place while providing lateral and torsional stability to the joists.

Bottom chords are fabricated with clips to accommodate rollbars if temporary bridging is needed during
the pouring process. Generally, no permanent bridging or shoring is required unless specifically noted.

4. SHEETS OF MESH
Welded wire mesh serves as the standard catenary for the slab. Standard 8 ft x 20 ft (2,400 mm x 6,100 mm) sheets of mesh are easily placed over the top chords of the Hambro joists. The top chord acts as a high chair.

5. CONCRETE POURING AND FINISHING
When pouring and finishing a Hambro slab, it is not necessary to complete the entire deck in a single pour. In the event that the pour is interrupted parallel to the joists, the joint should be midway between the joists, but never less than 6 in. (152 mm) from the top chord in order to ensure composite action.

6. REMOVAL OF PLYWOOD FORMS
When the concrete attains a cylinder strength of 500 psi (3.5 MPa), the rollbars and plywood forms can be removed. When the concrete attains a cylinder strength of 1,000 psi (7 MPa), the floor is ready but care must be taken not to surpass the admissible loads for the specified capacity.

Privileged on conventional structural steel framing

The Hambro MD2000 composite floor system is the ideal solution for a building whose structure is made of steel (beams and columns), but it can also be installed on other types of structure. It combines the flexibility of the Hambro steel joists with steel deck and a transversely reinforced concrete compression slab.

It is the answer to your multi-story building challenges with the advantage of enabling the pouring of concrete on more than one floor at a time. Composed of steel deck as a permanent form, it requires no stripping, allowing it to be quickly available for other trades.

Benefits

Fire resistance: The Hambro system complies with UL/ULC/cUL standards.

Long spans: Hambro joists can span up to 43 ft. (13.1 m) without shoring.

Rigidity and strength: Enhanced strength due to composite action between the steel and concrete.

Versatility: Applicable to all types of framing.

Service: Design assistance, value engineering and fast delivery.

Simplicity: Fast and simple to install.

Installation

This system is highly recommended by steel erectors.

1. POSITIONING OF JOISTS
The joists are placed on the walls or beams and positioned in compliance with the drawings issued for construction by Canam. The joist connection methods are also shown on the Canam drawings.

2. PERMANENT BOLTED BRIDGING
Permanent bridging is designed to provide lateral and torsional support for the joists in the non-composite stage. Top and bottom chords are fabricated with clips to accommodate bridging, if needed during the pouring process. Generally, no shoring is required unless specifically noted.

3. STEEL DECK
Together, the steel deck and bridging form a rigid diaphragm during construction, providing a safe platform for workers. The MD2000 system uses steel deck P-3606 which is delivered in bundles for easier installation.

4. SHEETS OF MESH
Welded wire mesh serves as the standard catenary for the slab. Standard 8 ft. x 20 ft. (2,400 mm x 6,100 mm) sheets of mesh are easily placed over the top chords of the Hambro joists. The top chord acts as a high chair.

5. CONCRETE POURING AND FINISHING
When pouring and finishing a Hambro slab, it is not necessary to complete the entire deck in a single pour. In the event that the pour is interrupted parallel to the joists, the joint should be midway between the joists, but never less than 6 in. (152 mm) from the top chord in order to ensure composite action.

For longer spans

The Hambro girder act as a principal beam supporting the Hambro D500 joists wich are installed perpendicular on each side. Developed for the multi-residential and commercial markets, the Hambro composite girder offers greater spans than the conventional steel girder while maintaining a minimum depth to adapt to the Hambro joists.

Designed to address the need for longer spans and better ductability, the Hambro composite girder is composed of a top and bottom chord, each made of two angle sections.

The web system consists of vertical and diagonal members.

The top chord S connector closes the opening between the two angle sections.

In addition to the S connector and where necessary for shear requirements can be shop-installed on the girder between the Hambro joists.

3D of a D500 joist and of a Hambro composite girder

Benefits

Composite action slab/girder: Using a concrete slab in the overall design of the girder allows a better span-to-depth ratio than that of a conventional girder.

Reduced number of columns: Ideal for floors requiring long spans since fewer columns are used.

Special camber design: Hambro girders and joists are designed with a camber according to the dead load of wet concrete, becoming level after the pour. This provides the flexibility to install the ceiling beneath the bottom chord in accordance with ULC and UL specifications.

Optimum design: Designed to carry multiple floor loads.

Connections to effectively transfer shear loads

Shear connectors

The longitudinal shear that occurs between the concrete slab and the steel girder is due to the action of the following four elements:

The joist shoes welded at regular intervals to the girder. This concept, patented under the name Shear Shoe, utilizes a secondary structural element (joist) to create the longitudinal shear of a primary structural element (girder).

The anchorage created by the end plate welded at each end of the girder. The horizontal force is associated with the resistance of the concrete.

The bond friction that occurs between the joist top chord S and the concrete slab.

The additional connectors used to support heavy loads (U-shaped steel channels welded to the girder at regular intervals). These U-shaped channels were developed in collaboration with the Centre de recherche industrielle du Québec (CRIQ) and are always installed in pairs (one welded on the top of each angle of the top chord member).

Connection details

The strength of composite action

The Hambro transfer slab is a floor system that transfers the superimposed loads from the structural building frame above the slab to the columns, walls and foundations below. This system is economical and lighter than conventional reinforced concrete slabs.

An alternative to reinforced concrete slabs

The transfer slab designed by Canam is composed of Hambro joists and girders in composite action with a concrete slab, which makes it easy to install.

Benefits:

Fire resistance: System complies with UL/ULC/cUL standards.

Acoustical properties: STC up to 57 / IIC up to 30

Economical: Requires less concrete and reinforcing steel, thus reducing job-site time and costs.